Field of the Invention
The invention relates to a method for determining the insertion angle of a core temperature probe having a plurality of temperature measuring points in a food to be cooked for controlling a cooking process.
The invention further relates to a control unit for a cooking appliance for carrying out such a method and to a cooking appliance comprising such a control unit.
Related Technology
Automatic cooking processes are used primarily in professional cooking appliances, but increasingly also in household appliances.
For this purpose, essentially a so-called core temperature probe, which measures the temperature in the interior of a food to be cooked using at least one measuring site, and a control electronics unit are used. Such an assembly is described in WO 93/16333 A1, for example. Here, a lance-type tubular part comprising at least three thermistors is described, which is connected to a control electronics unit. This invention is characterized in that the thermistors are connected to each other at a distance of 1 cm to 3 cm either in a star or triangular shape.
A plurality of control methods for controlling cooking appliances have been previously proposed, which are based on the evaluation of temperature measurements taking place by way of a core temperature probe in a food to be cooked. A core temperature probe generally comprises several thermocouples, which are arranged in a thin lance that is inserted into the food to be cooked so as to monitor the state of the food to be cooked during a cooking process and thus control the cooking process. Such cooking methods are disclosed in EP 2 178 341 A2 as well as EP 1 021 979 A1, for example
Because the temperature measuring points provided for in the lance do not always end up at the coldest point in the food to be cooked and are thus not always able to directly determine the core temperature of the food to be cooked, it takes some effort to calculate or estimate the actual core temperature based on the available measuring data. According to the related state of the art, this is only done when the measuring points are located far away from the actual core of the food to be cooked.
A description of a linear arrangement of temperature measuring points and of a method for considering the thermokinematics of the temperature values is known from DE 199 45 021 A1, for example. The temporal progression, the temperature difference between the measuring sites located in the food to be cooked, and the temperature measured outside the food to be cooked are used for controlling the process. Without providing a more detailed description, it is proposed to determine the core temperature of the food to be cooked by extrapolation or iteration. The drawback here is that, at present, no ideas exist as to how such a method could be implemented in concrete terms, in particular if no exact positioning of the core temperature probe has taken place. So as to prevent unfavorable placement of the core temperature probe, positioning aids are frequently employed in practice, which move the core temperature probe to a predefined position so as to reduce position errors of up to 1.5 cm both inside and outside the food to be cooked. However, this works only conditionally because the expansion of the foods to be cooked differs greatly and may change significantly, for example in the case of baked goods during baking. Because the determination of the core point and edges of the food to be cooked is imprecise, the cooking result from automatic cooking processes is often not good.
To prevent this, it is proposed in DE 103 32 021 B3 to enter the thickness of the food product. The drawback here is that this is inconvenient and cumbersome for the user. A technical solution for automatically measuring the thickness can be found in DE 43 02 190 A1. However, neither of the disclosures describes an option for a way to determine the core temperature of the food to be cooked.